A pile foundation of a building is constructed by building a ground foundation structure of the building, having at least one through hole and fitted through, adjacent to the hole, with at least two cables fixed to the structure and projecting upwards. Once the foundation structure is completed, a metal pile is inserted through the hole and subjected to a series of static thrusts to drive it into the ground; and, once driven, the top of the pile is fixed axially to the foundation structure. Each thrust is applied by a thrust device, which is set up on top of the pile, cooperates with the top end of the pile, and is connected to the projecting portions of the cables, which, when driving the pile, act as reaction members for the thrust device.
The pile comprises a constant-section rod; and a wide bottom head, which is connected integrally to the rod and substantially the same size across as the hole so as to fit through it. When driving the pile, the head forms, in the ground, a channel larger across than the rod, and, as the pile is being driven, substantially plastic cement is fed into the part of the channel not occupied by the rod, so as to form a cement jacket about the pile.
Especially in soft ground, the transverse dimensions of the head should be particularly large to form a relatively large channel in the ground and, hence, a cement jacket large enough to ensure the required stability. The transverse dimensions of the head, however, are limited by those of the hole, which, over and above a given size, seriously impairs the capacity of the foundation structure, and makes it difficult to fix the sunk pile axially to the foundation structure.